Fix Issue 1344: Weird mesh distorted bug

Animations require consistent names for points like Avatar Center between viewers
To fix this, we now use Avatar Center instead of Root at the lower levels,
but this is okay, we translate Avatar Center into Root at UI level!

indra/newview/character/avatar_lad.xml

@@ -408,7 +408,7 @@
        id="40"
        group="6"
        pie_slice="4"
-       name="Root"
+       name="Avatar Center"
        joint="mRoot"
        position="0 0 0"
        rotation="0 0 0"